During grain harvesting operations with draper headers for wheat, soybeans and rice, for example, there is typically a significant amount of crop residue that must be controlled at the header. If the residue is allowed to migrate into the interior of one or both of the left and right draper assemblies of the header, it can become lodged in critical areas and interfere with movement of the draper belts. In severe conditions, it can even cause the draper belts to stall out.
The problem is particularly egregious in the transition region between the cutterbar assembly and the front edges of the draper assemblies because the endless loop in the belts of the assemblies present exposed openings to the interior of the belts in that area. While belt guards in the transition region cover the open front of the draper belt assemblies against ingress of the grain as it is severed and displaced rearwardly, it is a challenge to effectively seal off the area from residue, particularly considering that the cutterbar assembly and draper assemblies are flexing up and down at various locations along their lengths due to changes in ground contour encountered by the advancing harvester.
Previous efforts to seal off this critical area have included the use of an upstanding rib on the exterior of each draper belt along its front edge that engages the underside of overhanging portions of the belt guards as the belt is moving along. This dynamic seal arrangement is disclosed, for example, in Application Publication No. US 2010/0043373 titled “Draper Belt with Crop-Retaining Rib” and assigned to the assignee of the present invention. The construction in the '373 Publication also utilizes an upright stationary wall under the overhanging belt guard and forwardly of the front edge of the top run of the belt, but the top edge of the wall is only in close proximity to the overhanging belt guard with no effort to maintain constant interference contact between the belt guard and the wall. Although the dynamic seal arrangement of the '373 Publication is helpful in reducing residue accumulation in unwanted areas of the header, there is a continuing need for improvement in that respect.